Well, there is a general trend that male names often (over a long time) become female names. It probably starts from the "We're having a boy so only thought of boy names" and when it's a girl they either create / use a feminine version IE Christopher vs Christine. Sometimes the go with the traditional masculine name anyway, and eventually some names shift. Leslie used to be considered a masculine name, but has shifted to be considered feminine, as one relatively recent example of this.
I don;t personally know of any that went from feminine to masculine, but I don't doubt that some exist as well.